/*
 * Copyright 1999-2011 Alibaba Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.dubbo.remoting.transport.dispatcher;

import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.extension.ExtensionLoader;
import com.alibaba.dubbo.remoting.ChannelHandler;
import com.alibaba.dubbo.remoting.Dispatcher;
import com.alibaba.dubbo.remoting.exchange.support.header.HeartbeatHandler;
import com.alibaba.dubbo.remoting.transport.MultiMessageHandler;

/**
 * @author chao.liuc
 *
 */
public class ChannelHandlers {
	
	public static ChannelHandler wrap(ChannelHandler handler, URL url) {
		return ChannelHandlers.getInstance().wrapInternal(handler, url);
	}

	protected ChannelHandlers() {
	}

	/** 包装委派处理器，心跳处理器，多消息处理器 */
	protected ChannelHandler wrapInternal(ChannelHandler handler, URL url) {
		ChannelHandler wrappedHandler = ExtensionLoader.getExtensionLoader(Dispatcher.class).getAdaptiveExtension().dispatch(handler, url);
		wrappedHandler = new HeartbeatHandler(wrappedHandler);
		wrappedHandler = new MultiMessageHandler(wrappedHandler);
		return wrappedHandler;
	}

	private static ChannelHandlers INSTANCE = new ChannelHandlers();

	protected static ChannelHandlers getInstance() {
		return INSTANCE;
	}

	static void setTestingChannelHandlers(ChannelHandlers instance) {
		INSTANCE = instance;
	}
}